Abstract: A portable device (10) for excising an axial slot (8) into the boundary surface (16) of an aperture (15). The device (10) includes a guide (11), a machining implement (12) and a power source (13). The guide (11) has proximal and distal ends (19 and 20) with an exterior configuration including at least a horn surface (26) and a transitional surface (30). A reaction flange (21) extends radially outwardly from the proximal end (19) of the guide (11). A slideway (35) extends longitudinally within the guide (11), and a tracking channel (36) extends radially outwardly from the slideway (35) to penetrate the guide (11) along the axial extent thereof.

Abstract: A method of inspecting a tube header bore comprises scoring an oxide scale layer within the bore using a hard scribing tool. The bore is then cleaned using one or more honing brushes having flexible bristles with carbide tips. After sufficiently cleaning the inner surface of the bore a florescent dye is applied to the surface for highlighting surface defects and a visual inspection is made. For easy access to the interior of the bore, the tube is cut at a point spaced from the bore. After the inspection is complete a new length of tube is connected such as by welding.